There is very little knowledge of products that use a plastic barrier system with a steel footplate. There is one known product that comprises a glass reinforced plastics (GRP) handrail system but this does not use a steel footplate for anchorage of the handrail system.
All the GRP systems use a loose fitting sleeve which fits over a mating projection. Once the GRP section has been fitted onto a moulded footplate, by means of a loose fit, the components then have to be additionally secured, for example using a fixing bolt, which will generally also be of steel.
In other words the loose fit items are not self supportive and they must be bolted together.